Credit

Caption

Sea lion. Thermogram of a sea lion with its mouth open. A thermogram shows variation in temperature on the surface of an object, measured by the long- wave infrared radiation it emits. The temperature scale is colour-coded and runs from purple (-8.1 degrees Celsius, coldest) through blue, green and yellow to light red (warmest, 32 degrees Celsius). The fur of a sea lion traps air to aid insulation. In addition to this it has an insulating layer of blubber, where this is absent, heat loss is greatest.